The phenomena of reduced viscosity bending up and sometimes appearing a maximum in extremely dilute concentration regime of polymer solution are resulted from the concentration reduction due to adsorption of polymer onto the glass capillary wall. A quantitative theoretical description of this effect based on Langmuir adsorption isotherm is given. Applying the deduced formula to fit Ohrn’s precisely measured reduced viscosity data of polystyrene, linear and branched polyvinyl acetate solutions for three viscometers with different capillary radius gave satisfactory results. The radius dependence of the effective adsorption layer thickness of these polymers indicates it consists of two parts, that is a true adsorption layer and a repulsion layer between anchored chains on the capillary surface and flowing chains in solution. The reduced viscosities of an ultrahigh molar mass polyethylene oxide sample in aqueous solution were measured both by an ordinary glass viscometer and by a viscometer constructed with a polytetrafluoroethylene capillary. The former exhibits a maximum due to adsorption and the later possesses the typical behavior of slipping flow. After correction for solute adsorption and slippage, respectively, the two sets of data coincide well and gave a common linear reduced viscosity plot down to extremely dilute concentration regime.

将聚甲基丙烯酸甲酯（PMMA）丙酮溶液分别在自然以及超声振动下成膜，所得薄膜分别作差示扫描量热（DSC）和裂解气相色谱-质谱（PyGC-MS）表征。分析结果表明：不同成膜条件下，高分子的凝聚态结构有所不同，试样中残留的溶剂量也有差别；自然挥发所得的初生态薄膜中残留的溶剂是超声作用下所得薄膜的12倍。

An investigation was carried out into the cure kinetics of carbon nanofibers (CNF)/epoxy composites, composed of tetraglycidyl-4,4 -diaminodiphenylmethane (TGDDM) resin and 4,4 -diaminodiphenylsulfone (DDS) as a curing agent. The experimental data for both neat system and CNF/epoxy composites revealed an autocatalytic behavior. Analysis of DSC data indicated that the presence of carbon nanofibers had only a negligible effect on the cure kinetics of the epoxy. Kinetic analysis was performed using the phenomenological model of Kamal and two diffusion factors were introduced to describe the cure reaction in thelatter stage. Activation energies and kinetic parameters were determined by fitting experimental data. Comparison between the two diffusion factors was performed, showing that the modified factor was successfully applied to the experimental data over the whole curing temperature range.

The special thermosensitive copolymer with lower critical solubility temperature near human heat of 37℃ in aqueous solution has been prepared successfully by copolymerizing N-isopropylacrylamide (NIPAM) and N-isopropylmethacrylamide (NIPMAM) randomly at an appropriate monomer ratio. The self-association behavior of the poly[NIPAM-ran-NIPMAM] copolymer has been studied by dynamic laser light scattering (DLLS) at a concentration higher than the critical concentration of the self-association calculated from viscosity data according to cluster theory. The effect of the concentration and temperature on the self-association behavior in water has been discussed respectively.

A poly(vinyl alcohol) hydrogel was prepared by coupling poly(vinyl alcohol) with epichlorohydrin as cross-linking agent. Various amounts of water were added into the dry hydrogel to swell it and the quantity of water in various states in the partially swollen hydrogel were determined by DSC ice-melting technique. A parameter S denoted the degree of the saturation of swelling was introduced for describing the various stages of water absorption. The analytical results indicate that there exists two critical threshold degree of saturation. At the first threshold S*, the freezable bound water starts to appear and at the second threshold S**, the free water begins to appear. In the region of S!S*, the adsorbed water exists only in the non-freezable form and increases linearly with S until reaching S*. The sum of non-freezable and freezable bound water consists of the hydration layer around the chain segments of the network. The hydration number HN of the repeating unit of PVA hydrogel increases from zero to a limiting value about 2.5 as the degree of saturation varies from zero to one.